Submersible cable pumping unit



. w. c. WOLF SUBMERSIBLE CABLE PUMPING UNIT Filed April 16. 1968 May 5, 1970 INVENTOR.

W/LL/AM 0. 6004/ amfoz/f AITORNEYS,

BY 5140M,

United States Patent ice 3,510,234 SUBMERSIBLE CABLE PUMPING UNIT William C. Wolf, 1828 Churchill Way, Oklahoma City, Okla. 73120 Filed Apr. 16, 1968, Ser. No. 721,882 Int. Cl. F04b 47/00, 9/02 US. Cl. 417-450 Claims ABSTRACT OF THE DISCLOSURE A reciprocating, cable operated, pump assembly for use in a Well casing, or the like, including a working barrel with a reciprocating plunger therein, an annular coupler secured to the upper end of the working barrel and seating an expandible packer ring for spreading engagement with the inner wall of the well casing, a downwardly tapered mandrel above said packing ring adapted to be forced into the packing ring and to spread the ring into engagement with the casing, said mandrel having a downwardly extending, coaxial, release tube passing through said coupler and terminating in a lift nut below the coupler which is adapted, during removal of the pump assembly from the well casing, to lift the mandrel and thereby release the packer ring from engagement with the casing, a driver tube above said mandrel secured at it upper end to a reciprocating cable, the lower end of said driver tube being engageable with said mandrel to drive the mandrel downwardly and spread the packer ring during setting of the pump assembly, a pump rod extending upwardly from said plunger through said coupler at the upper end of the working barrel and said mandrel and into said driver tube, means on said driver tube slidably receiving the upper end of said plunger rod and providing a coupling with said rod for lifting movements of the plunger during reciprocation thereof, and a compression spring seated between said coupler and a holding member fixed to said plunger rod to bias the plunger rod downwardly, whereby the packer ring may be released by pulling the cable up to compress said spring and cause said spring holder to strike the release tube on the mandrel, lifting the mandrel from spreading engagement with said packer ring and releasing the pump assembly to travel freely up and out of the well.

Background of the invention and description of the prior art This invention relates to improvements in reciprocating pumps of the type used below the surface for pumping improved pump assembly of this type which is operated by a wire cable extending downwardly in the well from the surface to the pump assembly.

As it is well-known in the art, many types of reciprocating sub-surface well pumps have been developed and extensively used. The great majority of these pumps, particularly in the oil industry, are operated by a string of sucker rods extending through the well from the surface to the pumping unit, which may be several thousand feet under the ground surface. These sucker rod type pumps require heavy and expensive equipment on the ground surface for reciprocating the rod string and operating the pump. Also, the rods are alternately subject to tension and compression to provide the up-and-down strokes of the pump, thereby causing the rods to fatigue in a relatively short period of time and resulting in frequent parting of the rod string, with an attendant loss of time and money in recovering the pump unit and placing the unit back in operation. In addition, the operation of installing and removing the pump requires an 3,510,234 Patented May 5, 1970 excessive amount of time in jointing and unjointing the various sections of the sucker rod string.

Several attempts have also been made to produce a subsurface well pump which may be operated by cable. Up to the present, however, a completely satisfactory pumping unit of this type has not been provided. One of the major problems in cable type pumps of the insert type is the provision of means for seating the pumps in the well tubing, or casing, such that the pump may be easily seated, and yet will remain in its seated position during operation of the pump. Heretofore pumps of this type have been provided with seating cups at the lower end of the pump which are inserted in a suitable shoe, or nipple. To be effective, these seating cups must have substantial friction against the seating shoe, thereby complicating the installation of the pump, since the cable cannot be used to force the pump into a seated position as in sucker rod type installation.

Summary of the invention The present invention contemplates an improved type cable pumping unit, which may be run in well casings of several different sizes and is designed with a packer at its top which is set by lowering a packer setter attached to the wire cable and the plunger rod of the pump unit. This unit requires no shoes or nipples in the well casing. The packer may be released by pulling the cable up to compress a spring in the pump return cage, causing the lower spring holder to strike the packer slip tube, releasing the packer rubber ring to free the pump to travel up out of the well. Oil in the pump, will drain to the bottom of the well, making for a dry and free pulling job.

The primary object of the present invention is to provide a cable type pump carrying a spreadable packer, for anchoring the pump to the well casing, and which may be easily set in the casing by a driver attached to the pump plunger and operating cable, said packer being released by pulling the cable to overload a spring in the pump unit and thereby lift the packer spreader.

Another important object of the invention is to provide a cable pumping unit including a traveling plunger with a ball valve and seat cage, said plunger being springloaded at all times so as to be sure of seating at a fast stroke.

A further object of the invention is to provide a cable pumping unit Whose plunger is spring-loaded and thus is not dependent upon the load of the cable or the weight of the liquid in the well casing to return the plunger on the downstroke.

Yet a further object of the invention is to provide a pump assembly, having the above described characteristics, which utilizes a polish tube sleeved over the cable and which slides in a packing gland at the well head at ground surface, the cable being secured to a pump jack by a special clamp at the top of the well.

Still a further object of the invention is to provide a cable pumping unit which utilizes the well casing, or tubing to transfer fluid from the bottom of the well to the surface.

A still further object of the invention is to provide a cable pumping unit which may be easily transported to the field for installation, and which may be serviced by one man, or by a very small servicing unit.

Brief description of the drawings The novel features which are considered characteristic of the invention are set forth with particularity in the appended claims. The invention, itself, however, both as to its organization and its method of operation, together with additional objects and advantages thereof, will best be understood from the following description of a specific embodiment when read in connection with the accompanying drawings, wherein like reference characters indicate like parts throughout the several figures, and III which:

The single figure is a sectional view of a submersible cable pumping unit in accordance with the present invention, and showing the interior and working parts of the device.

Description of the preferred embodiment Referring to the drawings, a submersible cable pumping assembly suitable for use in pumping oil from a deep oil well is illustrated as comprising a working barrel 38 having a packer generally indicated by reference numeral 37 at its upper end, a packer spreader, or mandrel 18 mounted thereabove, and a driver, or setting tube generally indicated by numeral 22, all mounted within an oil well generally indicated at 40, and comprising a well casing 39 capped by a header 29.

The working barrel, or eduction tube 38, is formed of an upper section 9 which houses a compression spring 13, and a lower section secured together by the annular, double threaded coupler 8. At the bottom of the working barrel, for seating at the oil bearing level, or strata, is a strainer 1 having a plurality of perforations in its wall and closed by a bottom plug 2, the upper end of the strainer being threaded into a nipple 3 formed as a ball valve seat and adapter for holding the ball cage 4 and the ball 44. The cage 4 has openings in its sidewalls to admit oil being pumped through the inlet formed at the ball valve seat into the working barrel, and the ball valve is preferably lightly biased against its seat by a spring guide 42 and compression spring 43. Within the working barrel section 5 and above the ball 44 is reciprocated a tubular plunger 6 having a ball therein similar to the ball 44, a seat therefor, and a ball cage 6a including a guide and a spring similar to those provided at 42, 43 previously described. The ball valve cage 6a is provided with apertures so that oil may pass through the plunger upwardly, lifting the ball valve and exiting into the bore of the working barrel 38. A rigid pull rod 7 is fixedly secured to the upper end of the plunger 6, and extends upwardly through the coupling 8 and into the Working barrel section 9 where, at its upper end, is fastened a coupler 10 which joins the rod 7 to an extension rod 11. The extension rod 11 continues upwardly and passes out of the working barrel, as will be later described.

The holder, or coupler 10 slides in the working barrel section 9, being guided for reduced friction therein by the sealing ring 12, and in order to permit upward flow of oil being pumped, has unnumbered passages extending therethrough parallel to the plunger rod 7.

An annular packer coupler 14 closes the top of the working barrel section 9 being secured thereto by external threads on its bottom collar, the plunger rod 11 passing through an axial bore therein. Seated between the bottom of the packer coupler 14 and the top surface of the plunger rod holder 10 is a relatively large and strong compression spring 13 which biases the rods and the plunger carried thereby downwardly. The downstroke of the plunger is limited by holder 10 striking divider 8.

The packer coupler 14 has an upstanding, unnumbered sleeve which, together with the upper surface of the coupler, forms an annular seat for a ring-shaped, rubber packer 19 whose upper edge is beveled downwardly and inwardly to receive the complementary bottom edge surface of a spreader, or mandrel 18, mounted above the working barrel. The bore of the mandrel 18 surrounds the plunger rod 11, and a coaxial slip, or release, tube 15 also surrounds the plunger rod 11. Tube 15 is screwed, or welded to the mandrel. Point 00 designates the point where the rod and tube emerge from the upper surface of the mandrel. The slip tube 15 passes through the packer coupler 14 and is slidable therein in sealing engagement with three unnumbered O-rings. A lift nut 16 is screwed on the bottom of the slip ring 15, spaced from the under surface of the packer coupler 14 when the working barrel is set in the well. When the working barrel is to be released and lifted from the well, holding member 10 will be lifted against nut 16 which, in turn, will engage the underside of the packing coupler 14, thereby lifting the slip, or release tube 15 with respect to the packer ring 19 so that the mandrel 18 will disengage the packer ring and allow it to return to its natural unspread condition out of contact with the well casing. To assist in this release, a rubber release spring 19a encircles the packer ring 19 compressing it radially inwardly. The force of this spring is, of course, overcome when the mandrel 18 is lowered with respect to the coupler 14, entering the packer and spreading it outwardly into contact with the well casing. Above the mandrel 18, four holes 21 are formed in the wall of release tube 15 to permit egress of pumped oil into the well casing above the working barrel. Downward flow of the pumped oil back into the well bottom is prevented by the seal afforded by the packer ring 19 with the well casing. The upper end of the release tube 15 is formed as a hook, or fishing tool catch 20, suitable to be clampingly engaged by a fishing tool for lifting the pump out of the well should the cable, or rods, part.

' The driver, or setting tube 41 is formed in two parts having a lower tubular section 22 connected to the upper tubular section by a double-threaded divider nipple 23. The upper plunger rod 11 passes through the bore of nipple 23 and is capped by a pair of nuts 11a screwed thereon, so that lifting of the driver tube 41 will engage the nuts 11a with the divider nipple 23 and lift the working barrel by engagement of the holding member 10 with the nut 16 on the slip tube 15, as previously explained. The upper end of the packer setting tube 41 is closed by a pull coupler 24 secured thereto in any conventional manner, and this coupler is also provided with a fishing tool hook similar to part 20, previously described. The bottom of the wire cable 26 is passed into the bore of the coupler 24 and knotted at 28, the securement being completed by a pair of semicircular wedge members 25 and a nut 27 closing the lower end of the bore passage. In this manner the bottom of the cable is securely clamped to the upper end of the packer driver tube 41.

The wire cable 26 extends to the surface of the well, at least one rubber cable protector 27a being fastened thereto at an intermediate portion. The well casing 39 is capped by a header tube 29 having an outlet conduit 36 connected in the sidewall thereof and leading to an 011 storage tank. The upper end of the header 29 is closed by an annular adapter nut 30 whose bore passes the wire cable 26 as well as a polish tube 31 clamped to the cable at its top by a seal and clamping member 33. The polish tube reciprocates with the cable and rides in a packing gland, or sleeve 32 installed in the bore of the adapter nut 30. The upper end of the wire cable is secured at 35 to a clamp, or pull unit, which is also hooked up to a conventional jack for reciprocating the cable and the attached pump assembly.

The installation, operation, and removal of the pump assembly will now be readily understood. To install the device, the working barrel and associated devices, such as the packer 37, spreader 18, and driver tube 41 are attached to the cable 36 at the cable holder 24 and the complete assembly with the cable 26 is run into the oil well casing 39 and set on the bottom of the well 40. The packer is then set to frictionally engage and clamp the well casing 39 by lowering the packer setting tube 41 further to engage the mandrel, or spreader 18, so as to force the packer rubber 19 into sealing engagement with the well casing 39, thus forming a hold-down for the pump assembly. The cable 26 is then pulled up sufficiently to tighten the cable against the compression spring 13. The polish tube 31 and packer gland 32 are installed over the cable and the cable is held by means of a special clamp and then hooked to the cable pull holder 35 which, in turn, is secured to the pump jack, not shown. The pump assembly, after removal of the special cable clamp mentioned, is ready to start pumping.

During pumping the jack, not shown, reciprocates the cable 26 in a conventional manner, raising and lowering the plunger 6. The ball valve 44, at the oil inlet at the bottom of the pump, permits entry of the oil through the strainer 1 past the valve seat and through the opening 4 in the valve cage into the working barrel 38, and yet prevents the return flow back down through the oil inlet in a conventional Way. In a similar way, the ball valve in the plunger 6 permits passage of oil upwardly through the plunger and out through the openings 6a in the plunger valve cage 6, return movement of such oil being prevented by seating of the ball on each upstroke of the plunger. Upstrokes of the plunger lift the pumped oil in the working barrel through the bore of the divider 8, through the unnumbered passages in rod holder 10, through the release tube and out the apertures 21 in the upper end of the release tube. At this point the pumped oil has left the working barrel and fills the upper portion of the well casing 39, being prevented from draining downwardly by the packer ring 19. As more and more oil is pumped, its level reaches the top of the well and the oil exits through conduit 36 to a storage tank.

When it is desired to remove the pump assembly from the well it is merely necessary to lift the wire cable 26 above its normal stroke height to overload and compress the compression spring 13 in the working barrel. This will cause the holder member 12 to strike the nut 16 and lift the slip tube 15, removing the spreader mandrel 18 from the packer ring 19. The rubber release spring 19a then returns the packer spring to its normal size, unsetting the pump assembly so that further lifting of the cable 26 will pull the device out of the well.

Although a certain specific embodiment of the invention has been shown and described, it is obvious that many modifications thereof are possible. The invention, therefore, is not intended to be restricted to the exact showing of the drawings and description thereof, but is considered to include reasonable and obvious equivalents.

Having thus completely and fully described the invention, what is now claimed as new and desired to be protected by Letters Patent of the United States is:

1. A reciprocating, cable operated, pump assembly for use in a well casing or the like, comprising a working barrel having an outer diameter less than the inner diameter of the casing for insertion of the working barrel in the casing; a well fluid inlet in the lower end of the working barrel, a valve in the lower portion of the working barrel for opening and closing of said inlet, a tubular plunger closed at its upper end except for outlet orifices slidably disposed in the working barrel above said inlet valve, a valve in said plunger for controlling fluid entry and passage through the plunger, an annular coupler secured to the upper end of said working barrel and seating an expandible packer ring for spreading engagement with the inner wall of the well casing to set and hold the working barrel in place and seal against downward flow of pumped fluid, a downwardly tapered mandrel mounted above said packing ring and adapted to be forced into said packing ring to spread the ring into engagement with the casing, said mandrel having a dowwardly extending, coaxial, release tube passing through said coupler and terminating in a left nut spaced below the coupler and adapted during removal of the pump assembly from the well casing to lift the mandrel and thereby release the packer ring from engagement with the casing, a .driver tube above said mandrel having means at its upper end for securement of a lift cable, the lower end of said driver tube being engageable with said mandrel to drive the mandrel downwardly and spread said packer ring during setting of the pump assembly, a pump rod extending upwardly from said plunger through said coupler at the upper end of the working barrel and said mandrel and into said driver tube, and means on said driver tube slidably receiving the upper end of said plunger rod and providing a coupling with said rod for lifting movements of the plunger during reciprocation thereof.

2. A pump assembly according to claim 1, wherein is additionally provided spring means in said barrel seated between the coupler and a member fastened to the plunger rod for biasing the plunger in a downward direction to speed up downward return movements of the plunger.

3. A pump assembly according to claim 2, wherein said member fastened to the plunger rod and seating one end of said spring means engages said lower end of the driver tube to lift the driver tube and release said packer ring upon overload compression of the spring means by lifting the cable beyond normal reciprocating height to unseat and remove the pump assembly.

4. A pump assembly according to claim 2, wherein each of said mandrel and driver tube is provided at its upper end with a fishing tool catch.

5. A pump assembly according to claim 2, in combination with a well casing having a header at its upper end, and a polish tube clamped to the cable and slidable through said header, said cable and polish tube reciprocating together through said header.

References Cited UNITED STATES PATENTS 1,347,806 7/1920 Fender 103-179 3,089,428 5/1963 Johnson 103-179 3,150,606 9/1964 Howe 1032l9 XR ROBERT M. WALKER, Primary Examiner US. Cl. X.R. 

